I found Riga to be an amazing place! Lots of fun and the women are incredible!

As far as the chain rings, if it is very dirty, use a stiff plastic bristle brush with your choice of cleaner. Personally, I stay away from water-based cleaners. If you can protect the paint with some cardboard, use mineral spirits.

Once clean, I find a cheap paint brush (3 for $1 in my case) and MS to be a very good choice. Dry with a scrap t-shirt.